Abstract:

A virus strain was isolated from samples of oviduct mucosa of breeder duck , which showed irregularity and reduction in egg-laying. The virus was identified as an H9N2 subtype avian influenza virus by haemagglutination inhibition test and polymerase chain reaction. Analysised by BLAST in GenBank database, the products of the PCR were all share 99% similarity with those of strain A/chicken/Shandong/6/96(H9N2), and the three genes fragment were all derived from the genes pool of H9N2 subtype avian influenza viruses. The phylogenetic analysis of HA gene showed that the fragment of the isolate was similar to that of the A/CK/BJ/94 lineage of H9N2 viruses.